This invention generally relates to a method and an apparatus for the biodegradation of organic matter and, more particularly, to a method and an apparatus capable of accelerated biodegradation of organic matter.
A typical method of biodegrading organic matter is a compost pile wherein bacteria are used to biodegrade the organic matter. During the biodegradation process the bacteria consume oxygen and produce primarily carbon dioxide, water, and energy. The energy is predominantly released as heat. The amount of heat generated in the center or core of the compost pile is sufficient to convert the water produced into water vapor, which diffuses outwardly from the center of the compost pile. To sustain the biodegradation process it is necessary to replace the oxygen consumed by the bacteria and to dissipate the heat produced during the biodegradation process. Failure to either replace the oxygen or dissipate the heat can kill the bacteria.
Dissipation of the heat generated in a typical compost pile occurs in several ways including convection, radiation, and emission of exhaust gasses including water vapor. In a typical compost pile the rate of heat dissipation is much greater at the outer surface than at the core. This differential heat loss creates a temperature differential between the core and the surface of the compost pile. The core of a typical compost pile reaches temperatures in excess of 50.degree. C. to 65.degree. C., while the surface of the compost pile remains at about the ambient temperature of the surrounding air, typically 25.degree. C. Such high core temperatures, if sustained, can kill the bacteria in the core of the compost pile. In addition, the temperature differential causes the water vapor diffusing from the core of the compost pile to condense on the surface of the compost pile and the condensed water percolates back into the compost pile.
Unless the compost pile is periodically agitated, depletion of oxygen occurs, especially at the core of the compost pile, because the oxygen cannot diffuse to the core as rapidly as the oxygen is initially consumed by the bacteria during the biodegradation process. The net result of the lack of dissipation of heat from the core of the compost pile and failure to replace the oxygen in the compost pile is that the steady-state biodegradation rate reaches an equilibrium that is very slow compared to the potential biodegradation rate.
In a typical compost pile the energy generated as heat is lost because this energy is not efficiently captured when produced and the condensation of water vapor on the surface of the compost pile further recaptures energy produced by the biodegradation and returns it to the pile.
Therefore, it is desirable to provide a method and apparatus which will permit more efficient control of the rate of heat transfer from the compost pile to the surrounding atmosphere and more efficient regulation of the oxygen content within the compost pile to achieve a maximal biodegradation rate in the pile. In addition, it is furthermore desirable to capture the energy produced by the biodegradation of the organic matter.